1. Box Model for the GSL Hydrologic System Thuan Chau, Mason Edwards NASA 2003

2. Box Model E.T. DB P DB E GSL P GSL Q Drainage Basin (DB) Great Salt Lake (GSL) Bear River Weber River Utah Lake Horsburgh 2010

3. H 2nd = - 4E-06x 2 + 0.0286x + 4165.1 H 3rd = 5E-10x 3 - 7E-06x 2 + 0.0333x + 4163.4 H 4th = 4E-14x 4 + 9E-11x 3 - 6E-06x 2 + 0.0323x + 4163.6 H 5th = 4E-16x 5 - 4E-12x 4 + 1E-08x 3 - 3E-05x 2 + 0.0461x + 4161.4 H =4.5E-10x 3 – 7.4E-06x 2 + 0.0338x + 4163 Polynomial Determination Curry 1984

4. P DB (m/yr) P GSL (m/yr) ET DB (m/yr) E GSL (m/yr) Area DB (mi 2 ) Area GSL (mi 2 ) Surface Elevation Model (ft) Surface Elevation Record (ft) Difference (%) Current 0.420.290.331.141300013764197 0 Gilbert 0.660.480.331.14130006593419442501.32 Provo 0.880.640.331.141300014430446247405.86 Bonneville 0.980.710.331.141300019674539150905.91 Stansbury 0.760.550.331.14130009356420045006.67 Conditions to Reproduce Prehistoric Shorelines Model Limitations and Further Considerations: Effect of isostasy Change in evapotranspiration with lake level